00:01
Alright, hello! in this question we're given this circuit diagram, and we're asked to use kirchhoff's rules in order to find the values for i1, 2, and 3.
00:08
We're actually only asked for i2, but we're going to go ahead and just solve for all of them.
00:12
So i'm going to start by using the junction rule here at node a.
00:16
So i know that i1 plus i2 is going to equal i3.
00:20
What's going in equals what's going out.
00:22
And then i'm going to do two loop rules here, one for the left loop.
00:25
I'm going to start down here at node b, and i'm going to go in the direction of the arrow there.
00:31
So if i start, i'm going to gain 20 volts at that voltage source, and then i'm going to lose i1 times r1.
00:38
I'm just going to write down what the numerical values are instead of symbolic values here.
00:44
And then i go through r3, so i'm also going to lose i3 times r3.
00:50
And then i'm going to go from positive to minus on that voltage source, so that's going to be a loss of 5 volts.
00:56
And that's going to get me back to where i started, so that's going to equal 0...